Cutting machine and knife therefor



June 22, 1954 H. H. FALKMAN ET AL 2,681,669

CUTTING MACHINE AND KNIFE THEREFOR Filed Feb. 24, 1950 4 Sheets-Sheet l BVM WM" M June 22, 1954 H. H. FALKMAN ET Al. 2,681,569

CUTTING MACHINE AND KNIFE THEREFOR Filed Feb. 24, 1950 4 Sheets-Sheet 2 Fig. 2

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{"l L 5 2 Si 24 ,5 /6 26 I3 June 22, 1954 H. H. FALKMAN ETAL CUTTING MACHINE AND KNIFE THEREFOR 4 Sheets-Sheet 3 Filed Feb. 24; 1950 @fn/gd June 22, 1954 H. H. FALKMAN ET AL 2,681,669

CUTTING MACHINE AND KNIFE THEREFOR Filed Feb. 24, 1950 4 Sheets-Sheet 4 Patented June 22, 1954 UNITED STATES PATNT OFFICE CUTTING MACHINE AND KNIFE THEREFOR Application February 24, 1950, Serial No. 146,104

Claims priority, application Sweden March 1, 1949 Cl. D14- 208) 17 Claims.

The present invention relates to cutting machines comprising a rotatable cutter assembly and particularly intended for removing bark from logs. Such machines may preferably be provided with a cutter assembly having at least one knife adjustable relative to a hub of the cutter assembly while the cutter assembly is rotating in order to fit different curvatures of a log.

One object of the invention is to provide a portable or hand held cutting machine of this type suitable for removing bark from logs having varying diameters. Some elements of the invention, however, may be used or employed in other cutting machines and are consequently not limited to cutting machines for removing bark from logs. During operation of a cutting machine embodying the invention for removing bark from logs, the cutting machine is moved longitudinally of the logs with the axis of rotation of the cutter assembly directed transversely of the log. During said movement the knives of the cutter assembly which have curved edges are adjusted automatically in accordance with the varying curvature of the log. In a preferred embodiment of the invention the cutter assembly is provided with at least one knife adjustable during the rotation of the cutter assembly on a turning axle for said knife extending parallel to the axis of rotation of the cutter assembly and substantially coincident with an axis passing through the center of gravity of the knife parallel to said axis of rotation. The invention also includes the separate knives for such cutting machines.

A further object of the invention is to provide a simple and efficient shape of the knife which ts logs of greatly varying diameters and is cheap in manufacture, and a still further object is to obtain an arrangement providing ample space for removing the cuttings so that the knives are not clogged with cuttings and a still further object is to produce a knife requiring small forces for adjustment of the knife in accordance with different curvatures of the log.

In the accompanying drawings a bark removing machine embodying the invention and two forms of knives for cutter assemblies of such machines are illustrated by way of example. Fig. 1 is a side view and partial section of a bark cutting machine. Fig. 2 is a rear view and partial section on line II-II in Fig. 1. Fig. 3 is a rear view of the bark cutting machine as viewed in the longitudinal direction of a log, certain parts, such as the rear operating handle, being omitted. Figs. 4 and 5 are detail views illustrating one form the motor.

of cutter knife and Fig. 6 is a detail view illustrating another form of cutter knife.

The bark cutting machine illustrated in Figs. 1 to 3 consists of a housing i in which a cutter assembly is journalled. Said cutter comprises a rotatably mounted assembly including a hub portion Icomprising a hollow shaft 2, yand other members associated therewith including one or more adjustable knives rotating therewith and hereinafter more fully described. rIhe housing I has a support 3 carrying a motor 4 which may be a compressed air driven motor, an internal combustion motor, an electric motor, or any other suitable motor. The shaft 5 of the motor 4 carries a pulley 6 for a V-belt 'I which drives a Wheel 8 secured on the shaft 2 of the cutter assembly. The V-belt-drive is protected by a cover 9 which is omitted in Fig. 2 and which is carried by the housing i. The housing i which covers the cutter assembly is provided with handles in front of and at the rear side of the cutter assembly, one of said handles It being directed in the feeding direction of the cutting machine, i. e. lengthwise of the log, whereas the other handle II extends transversely of the feeding direction of the machine so that it may be held steadily in all different positions which may be desired during barking of a log. In the illustrated embodiment the motor ci is a compressed air driven motor, and a supply conduit 4I for compressed air is carried through the handle lil to For controlling the operation of the motor a regulating valve of conventional design may be provided in the handle IIB.

Apart from the shaft 2 the hub of the cutter assembly comprises two discs I2 and I3 forming bearings for three band-shaped knives I4 rotatably journalled on trunnions I5 in said bearings. The trunnions I5 provide an axis for the knife parallel to the axis of rotation of the cutter assembly and passing through the center of gravity of the knife. For convenience and brevity such axis will hereinafter be referred to as the gravity axis of the knife. The number of knives may naturally be more or less than three. The knives I4 comprise an intermediate bandshaped portion I6 extending substantially parallel to the gravity axis through the trunnions I5 and parallel to the axis of rotation of the cutter assembly. The knives are formed with side Walls or members il and I8 extending transversely of the turning axle provided by the trunnions I5. Said members on one side form toothed segments I9 which merge into weighted portions 20 that serve to counterbalance the bandshaped portion i6 relative to the turning axle. The teeth IB engage teeth 2l and 32 on a sleeve 23 which is rotatable but axially non-displaceable relative tothe cutter assembly shaft 2. Internally the sleeve Z3 is provided with two straight axial grooves 24 engaged by the ends of a cross pin 25. Said pin 25 extends transversely of the cutter assembly shaft 2 through a head 26 provided on a regulating rod 2l which is slideable longitudinally ofthe cutter assembly shaft. The pin 25 projects through helical openings 28 in the wall of the cutter assembly shaft and coopn erates withV the walls of said openings and the walls of the grooves 24 to cause a relative rotation of the sleeve 23 with respect to the discs i2 and I3 when the pin is displaced axially inthe cutter assembly shaft by means of the regulating rod 2l. Since the discs i2 and i3 are xed on the shaft 2 and carry the rotatable knives lli said relative movements may be used to cause the l knives l to be adjusted from a position in which they cut flush t'o a position in which they cut along a lcurve corresponding substantially to the curvature of a log with a given small diameter. In Figs. l and 2 the knives are illustrated in the last mentioned position of adjustment. In all intermediate positions the knives cut along curves substantially corresponding to the curvature of logs with larger diameters. A spring 23 mounted within the shaft 2 tends to move the .i

head 23 with the `cross pin 25 to a position to the right in Fig. 2 in which the cutter assembly is adjusted for removing bark from logs with the smallest diameter.

The displacement of the regulating rod 2l is produced automatically by impulses obtained from the log which is being barked and which in Fig. 3 is designated by 39. For this purpose two levers 3E and 32 are swingably journalled at 5I, 5i on the housing i links 33 and 3d and a pivot pin Sil with an arm 35 of a bell crank lever 35, 33 journalled in a bearing 3l carried by a bracket 3l 'on the housing l. The levers 3i and 32 form feelers which with rollers 3% and 39 travel on the log with one feeler 'on leach sid'e of a path on the log along which a `central supporting roller il@ for the machine travels. rihe arm 35 of the bell crank lever 35, 35 engages the 'end i2 of the regulating rod l2l by means of a bearing formed on said arm so that axial forces may be transmitted to and from the rod 2l while said rod rotates with the cutter assembly. Obviously, when the machine is moved along a log the rollers 38 and 33 due to the force of the spring 29 and/or a due to their weight are pressed against the surface of the log. Since 'the rollers 3s and 33 and the supporting roller t@ simultaneously rest on the log, the rollers 33 and 3S and the supporting roller "dil always take certain relative positions which are functions of the curvature of the log and which in a cutting machine 'embodying the invention are utilized to displace the regulating rod 2l longitudinally of the shaft 2 and thereby adjust the knives lll to correspond to said curvature of the log. Since each knife is adjusted merely by a partial rotation in either direction about its 'gravity axis the force necessary for adjusting the knife is very small even when the cutter assembly runs at a high number of revolutions. automatic adjustment of the knives without the use lof means interfering with the working area of the knives is obtained.

In the cutting machine illustrated an auxiliary and connected through L Consequently, a quick and safesupport is provided at the front end of the machine, said support being formed by a roller 43 which is resiliently mounted by means of a spring el!! in the housing I at the end of the machine opposite from the supporting roller 30. By pressing the handle l! downwardly more or less the operator may at will change the depth of the cuts due to the provision of the spring 44.

It is to be noted that upward movement of the rollers 3B and 39 and the arms 3| and 32 about the pivot points 5l, 5I is opposed by the spring 29 and that the path of movement of the pivot pin 34 upon upward or downward movement of the rollers 38 and 39 is arcuate. However, this arcuate path is controlled with relation to the Aframe of the machine by an arm 35 of bell crank lever 35, 36 which is pivoted on bracket 3l' attached to the frame and since arm 35 provides a relatively long radius, the path of movement of the pivot pin 34' approaches a straight line. In any event the deviation from straight line motion of the pivot pin 311 is so slight that upward and downward movement of the rollers 33 and 39 with relation to the frame is substantially symmetrical and lconsequently these rollers will engage the log 30 and guide the machine in a substantially straight line during the cutting operation.

In Figs. 4 and 5 the knife i4 is illustrated on a larger scale. Fig. 4 is a perspective view of said knife, and Fig. 5 illustrates the knife as Viewed from the cutter shaft. The two `figures illustrate a suitable curve of the knife edge which curve is so shaped that the edge of the of theV knife shown in Figs. 4 and 5.

knife in different positions of adjustment substantially corresponds to the curvature of logs of different diameters. The side members Il and i8 of the knife are provided at the lower forward portion with a bark-slitting edge ri which makes the knife work easier in thick bark. The other parts of the knife of Figs. e and y5 have already been described.

The knife illustrated in Fig. 6 is a modification The portions of the knife which are substantially the same have been designated with the same reference numerals and are not described again. The difference consists substantially in the fact that the band-shaped portion it has been extended at lthe sides of the knife so as tc form portions Y4'! and i8 projecting outside the side members l1 and I8 and forming edges 33 and 53 parallel with the gravity axis of the knife. By this arrangement the capacity of the cutter va'ssenibly is materially increased when it comes to removing bark from logs with large diameters. The Yedges 56' are Yin this case disposed somewhat inside the outer side surfaces of the members Il and '13.

The bark cutting machine above described and illustrated in the drawings as wel-l 'as the above described and illustrated knives for such cutting machines should only be considered as examples and may be modified in several different ways within the scope of the claims. The number of knives on the cutter assembly may of course be varied accordingto the number of revolutions and the size of the cutter assembly.

What we claim is:

l. A cutting machine comprising a 'rotatablyA mounted cutter assembly hav-ing a hub portion and including at least one knife, said lknife being mounted to turn relative to said hub portion about van axis 4subst'ant-ially co-incident with the;

gravity axis of said knife and parallel to said axis of rotation of said cutter assembly.

2. A cutting machine comprising a rotatably mounted cutter assembly having a hub portion and at least one knife adjustable relative to said hub portion, while the cutter assembly is rotating, about a turning axis substantially co-incident with the gravity axis of the knife and parallel to the axis of rotation of said cutter assembly, said knife comprising a band shaped portion extending substantially parallel to said turning axis and portions extending transversely of said turning axis, said transversely extending portions comprising means for mounting the knife to turn on said turning axis and including means for counterbalancing said band shaped portion with respect to said turning axis.

3. A cutting machine as defined in claim 2, in which the portions of the knife extending transversely of said turning axis comprise two side members located at the ends of the band shaped portion of the knife.

fi. A cutting machine comprising a rotatably mounted cutter assembly having a hub portion and at least one knife adjustable relative to said hub portion, while the cutter assembly is rotating, about a turning axis substantially co-incident with the gravity axis of the knife and parallel to the axis of rotation of said cutter assembly, said knife comprising a band shaped portion extending substantially parallel to said turning axis and portions extending transversely of said turning axis, said transversely extending portions comprising means for mounting the knife to turn on said turning axis, counterbalancing means for counterbalancing said band shaped portion with respect to said turning axis and means for transmitting turning movement to the knife to adjust the position thereof relative to the hub portion of the cutter assembly.

5. A cutting machine comprising a rotatably mounted cutter assembly having a hub portion and including at least one knife adjustable relative to said hub portion while the cutter assembly is rotating, said knife comprising a band shaped portion, portions extending transversely of said band shaped portion and providing two spaced side members each disposed inwardly from an end of said band shaped portion, and means for mounting said knife to turn relative to said hub portion about an axis substantially co-incident with the gravity axis of said knife and parallel to the axis of rotation of said cutter assembly.

6. A cutting machine for debarking logs comprising a rotatably mounted cutter assembly having a hub portion and at least one knife, means for mounting said knife to turn relative to said hub portion, while said cutter assembly is rotating and about a turning axis substantially coincident with the gravity axis of the knife and parallel to the axis of rotation of said cutter assembly, and means engaging a log at a place spaced from the cutter assembly and operatively connected with said knife for automatically adjusting the position of said knife relative to the hub portion of the cutter assembly and in accordance with the curvature of the log.

7. A cutting machine for debarking logs comprising a rotatably mounted cutter assembly having at least one knife adjustable while the cutter assembly is rotating to nt different curvatures of a log, means providing a support for the machine, said means being disposed in the longitudinal central plane of the machine and being spaced from the cutter assembly, two feelers at the sides of the machine in spaced relation to the cutter assembly and located so as to move along the log along paths at the sides of the path of movement of said support, and means for transmitting relative movement between said support and said feelers to said knife to adjust the knife in accordance with diierences in curvature of the log.

8. A cutting machine as defined in claim '7 in which said feelers comprise levers journalled on the machine to swing relative thereto.

9. A cutting machine as defined in claim 8 in which said levers are mounted to swing in planes transversely of the direction of feed of the machine along the length of a log.

l0. A knife for use as one element of a rotary cutter assembly comprising spaced supporting means for turnably supporting said knife about a turning axis on said cutter assembly during rotation thereof, a band shaped cutting portion extending substantially parallel to said axis and portions extending transversely of said axis, said transverse portions providing said supporting means and including means for counterbalancing said band shaped portion with respect to said turning axis.

11. A knife for a machine of the character described comprising spaced supporting means for turnably supporting the knife about a turning axis, a band shaped portion between said supporting means and portions extending transversely of said turning axis, said portions carrying said supporting means and having means thereon for transmitting turning movement to the knife about said axis.

l2. A knife for a machine of the character described comprising spaced supporting means for turnably supporting the knife about a turning axis, a band shaped cutting portion located between said supporting means, portions extending transversely of said band shaped portion and providing two spaced side members each located inwardly of an end of said band shaped portion, said side members carrying said spaced supporting means.

13. A cutting machine for debarking logs comprising a frame, a cutter assembly rotatably mounted on said frame, outwardly and downwardly extending arms pivotally mounted at their inner ends on said frame, log engaging rollers mounted on the outer ends of said arms and spaced from said cutter assembly longitudinally of said frame, a pair of links pivotally connected to said arms and to each other at their inner ends by a pivot pin, said pin being movable up and down in response to upward and downward movement of said arms and rollers, spring means for opposing upward movement of said pin, and means for controlling the path of movement of said pin relative to said frame to cause substantially symmetrical upward and downward movement of said rollers whereby said rollers may engage a log to guide said machine in a substantially straight line during operation of said cutter assembly to remove bark from the log.

14. A cutting machine for debarking logs comprising a frame, a cutter assembly rotatably mounted on said frame, outwardly and downwardly extending arms pivotally mounted adjacent their inner ends on said frame, log engaging rollers mounted on said arms and spaced from said cutter assembly longitudinally of said frame, a pair of links pivotally connected to said arms and to each other by a pivot pin, said pin being 7 movable up and down in response to upward and downward movement of said arms and rollers, resilient means for opposing upward movement of said pin, and means for controlling the path of movement of said pin relative to said frame to cause substantially symmetrical upward and downward movement of said rollers whereby said Y rollers may engage a log to guide said machine in a substantially straight line during operau tion of said cutter assembly to remove bark from the log.

15. A cutting machine for debarking logs comprising a frame, a cutter assembly rotatably mounted on said frame, outwardly and downwardly extending arms pivotally mounted on said frame, log engaging rollers mounted on said arms, a pair of links pivotally connected to said arms and to each other by a pivot pin, said pin being movable up and down in response to upward and downward movement of said arms and rollers, resilient means for opposing upward movement of said pin, and means for controlling the path ci movement of said pin relative to said frame to cause substantially symmetrical upward and downward movement of said rollers whereby said rollers may engage a log to guide said machine in a substantially straight line during operation of said cutter assembly to remove bark from the log.

16. A cutting machine for debarking logs comprising a frame, a cutter assembly rotatably mounted on said frame to rotate about an axis extending transversely of the length of the log, log'engaging rollers mounted on said frame for upward and downward pivotal movement about axes at right angles with the aXis of rotation ci the posing upward movement of said rollers and means for causing substantially symmetrical cutter assembly, resilient means for op upward and downward movement of said rollers relative to said frame whereby said rollers may engage a log to guide said machine in a substantially straight line during operation of said cutter assembly to remove bark from the log.

17. A bark cutting machine comprising a frame, a cutter mechanism rotatably journalled in said frame, log engaging rollers mounted on said frame for upward and downward movement and each having its axis of rotation'disposed in a plane parallel to the axis of rotation o said cutter mechanism, resilient means for opposing upward movement of said rollers, and means for causing substantially symmetrical upward and .downward movement of said rollers relative to said frame whereby said rollers may Vengage a log to guide said machine in a substantially straight line perpendicular to said axis of rotation of the cutter mechanism during operation of said cutter mechanism to remove bark from the log.

References cited in the sie of this patent UNITED sTATEs PATENTS 

